When jet-powered aircraft land, the landing gear brakes and imposed aerodynamic drag loads (e.g., flaps, spoilers, etc.) of the aircraft may not be sufficient to slow the aircraft down in the required amount of runway distance. Thus, jet engines on most aircraft include thrust reversers to enhance the stopping power of the aircraft. When deployed, thrust reversers redirect the rearward thrust of the jet engine to a forward direction to decelerate the aircraft. Because the jet thrust is directed forward, the jet thrust also slows down the aircraft upon landing.
Various thrust reverser designs are commonly known, and the particular design utilized depends, at least in part, on the engine manufacturer, the engine configuration, and the propulsion technology being used. Thrust reverser designs used most prominently with turbofan jet engines fall into three general categories: (1) cascade-type thrust reversers; (2) target-type thrust reversers; and (3) pivot door thrust reversers. Each of these designs employs a different type of moveable thrust reverser component to change the direction of the jet thrust; however, each is designed to enhance the stopping power of the aircraft, thereby shortening the stopping distance during landing. Hence, thrust reversers are primarily deployed during the landing process to slow the aircraft. Thereafter, when the thrust reversers are no longer needed, they are returned to their original, or stowed, position and are locked.
The thrust reverser components may be moved using hydraulic, pneumatic, or electric (electromechanical) actuation systems. Actuation systems typically include at least a controller and actuators each connected to a moveable shaft. During thrust reverser operation, some of these components may be prone to exposure to extreme pressures and temperatures. To isolate these components from the extreme environments, a firewall is typically used. In some configurations, the shaft passes through an opening in the firewall and a fireproof seal is mounted to the firewall to ensure that unwanted extreme temperatures do not pass through the opening.
Although conventional fireproof seal assemblies are generally effective, they may suffer from certain drawbacks. For example, in some configurations, the seal assembly may not allow the actuator to move in a sufficient number of degrees of freedom. Thus, the actuator may not function as desired. In other configurations, it may be relatively difficult to mount the seal assembly to the actuator. In particular, some of these components, such as the shaft, may be relatively heavy to lift or unwieldy to handle. Additionally, mounting the seal to the shaft may require a large amount of force, which may necessitate the involvement of more than one assembler. Consequently, maintenance or assembly of the actuator may not be as time and/or cost efficient as desired.
Accordingly, it is desirable to have a fireproof seal assembly that provides sufficient freedom of movement to the actuator. In addition, it is desirable to have a fireproof seal assembly that is relatively simple and time-and cost efficient to install. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.